Device for utilizing a diesel engine as a vacuum generator



July 24, 1962 L. PERAS 3,045,434

DEVICE FOR UTILIZING A DIESEL ENGINE AS A VACUUM GENERATOR Filed March 17, 1959 VACUUM T4 NK /4 I 4* Q VACUUM OPERATED @[G'ULATOR United States. Patent 3,045,434 DEVICE FQR UTHLIZING A DIESEL ENGINE AS A VACUUM GENERATOR Lucien Pras, 8/10 Ave. Emile Zola, Billancourt, France Filed Mar. 17,1959, Ser. No. 799,919 Claims priority, application France Mar. 18, 1958 4 Claims. (Cl. 6060) In automobile vehicles it is frequently necessary to have a source of vacuum for actuating various auxiliary equipments such as brakes, regulators, horns, etc.

The necessary vacuum may be obtained either by means of an engine-driven vacuum pump or, in a simpler and more economical way, by utilizing the suction available in the induction manifold of the engine.

The use of the suction produced in the induction manifold is relatively simple in petrol engines as the suction developed therein attains relatively considerable values, but in the case of a diesel engine it is attended by some difficulties as the value of the suction available is considerably lower.

Now it is the object of this invention to solve this problem by utilizing in diesel engines the suction produced by the engine induction cycle for the benefit of a vacuum reservoir by closing under predetermined conditions the induction pipe of the engine by means of a shutter. This shutter remains closed from the moment the operator releases the accelerator pedal until the next acceleration takes place, or in any case until such time as the engine speed has dropped to a relatively low value sufiicient however for enabling the engine to resume and maintain its idling speed.

According to a preferred embodiment of this invention, the shutter is of the conventional butterfly type and is actuated in the pipe-closing direction by an electromagnet having its energizing circuit controlled by 'the joint influence of means responsive to the position of the accelerator'control member, which means comprise an electric back contact (i.e. closed in its inoperative position), and of means responsive to the engine speed which comprise an electrical front contact (i.e. open in its inoperative position) mounted in series with said back contact and adapted to remain closed as long as the engine is running at a predetermined speed above the idling speed.

The vacuum reservoir is connected to the induction pipe at a point situated downstream of the shutter, a non-return valve being inserted in this connection.

In the case of an engine equipped with a vacuumactuated regulator this shutter may bemerged into one with the air shutter and mounted with a certain angular 0 play relative to the corresponding lever of the accelerator control linkage, the electromagnet being rigid with this lever and therefore adapted to close the shutter completely When the accelerator pedal is released, the shutter remaining closed as long as the engine runs faster than said predetermined speed.

In a similar arrangement the shutter may be separated from the regulator shutter and mounted for angular movement relative to the electromagnet support the latter being rotatably fast with the regulator-shutter operating lever. 7

It will be noted that in the case of diesel engines equipped with vacuum-operated regulators, which are conventional governors provided for diesel engines of all types and which serve to control the idling of the motor and the maximum output thereof, it is possible to bring about the automatic stoppage of the injection during the operation of the device, provided that the vacuum line leading to the regulator be branched off the induction pipe downstream of the shutter of the device. Similarly, it is advantageous to provide an operative coupling between this shutter and the regulator shutter because its useful movement is reduced to a simple relative angular movement. Finally, the means responsive to the released position of the accelerator pedal constitute a reliable safety against the undesired or untimely actuation of this shut ter during the acceleration stroke of the pedal.

In the case of an engine having a mechanical or hydraulic regulator the shutter is controlled by the electrical circuit in the same fashion as broadly set forth hereinabove and from the electromagnet support which may be fixed, provided that the permissible length of the stroke accomplished by the electromagnet plunger is sufficient to close and open the shutter completely.

In order to afford a clearer understanding of this invention and of the manner in which the same may be carried out in the practice, reference will now be made to the accompanying drawing forming part of this specification and illustrating diagrammatically by way of example two specific forms of the invention. In the drawing:

FIGURE 1 is a diagrammatic View illustrating a diesel engine induction pipe equipped with a device according to this invention, a shutter separate from the air shutter of the regulator being provided, the device being shown in its operative position;

FIGURE/2 is a similar view showing the device during an acceleration;

FIGURE 3 is a diagrammatic view illustrating a modified form of embodiment of the device wherein the shut- I ter constitutes at the same time the regulator air shutter.

Referring first to FIG. 1 the reference numeral 1 designates the induction pipe of a diesel engine, in which the air shutter 2 of the vacuum regulator or governor R is mounted, this regulator being connected to the pipe 1 downstream of the shutter 2 by means of a conduit 3. As in conventional mountings the shutter 2 is connected to the accelerator control member but in this case the linkage comprises a rod 4 connected at 5 to .an external bell crank 6 rigid with its fulcrum pin 7 on which the shutter 2 is secured in the pipe 1. The bell crank 6 co-acts in the direction of the accelerator control to its inoperative position with an adjustable stop consisting for example of a screw 8 for adjusting the engine idling speed by maintaining the shutter in a partially open position. Associated with the conventional assembly is the device of this invention which comprises in this example a separate shutter 9' spaced from the accelerator shutter and adapted, under the conditions set forth hereinabove, to close the induction pipe 1. Downstream of this shutter 9 is a pipe line 10 leading from the induction pipe to a vacuum reservoir T protected by a non-return valve 30 inserted in this line.

The shutter 9 is mounted for free angular movement relative to a pivoting lever 11 disposed externally of the pipe and operatively connected through a link 12 to the lever 6. The shutter 9 and lever 11 are pivoted about a common pin 13 but the lever rotates freely on this pin whereas the shutter is rigid therewith. This shutter 9 is displaceable relative to the lever 11 by means of an electromagnet 14 carried by the lever and provided with a movable core 15 having a projecting pin 16 engaging the forked end of an arm 17 solid with the pin 13 and therefore with the shutter 9.

The movable core 15 is normally urged to a position remote from the electromagnet winding 14 by a spring 18, and in this position the forked arm 17 engages a stop 11 adjustable or not said rigid with the lever 11. In this position the shutter 9 is substantially parallel to the regulator shutter 2 and from the foregoing it is clear that when the electromagnet 14 is energized the core 15 actuates the lever 17 and therefore the shutter 9 to its closed position (FIG. 1). The electrical circuit leading to the electromagnet winding is responsive to means for detecting the position of the accelerator pedal and to other means for detecting the engine speed.

The position of the accelerator pedal is detected in this case by means of an extension s of lever 6 which co-acts with an electric contact 19 comprising a movable blade 19 urged to its contact-opening position by a spring 20, this contact closing when the accelerator pedal is in or close to its released position. The function of the engine speed detector is to close an electric contact 21 in series with contact 19 in the circuit of the electromagnet 14 as long as the engine is running at a speed slightly greater than the idling speed.

The detector shown herein consists of a relay 22 having its coil connected across the positive terminals of the dynamo or generator 23 and of the storage battery 24 of the vehicle. This relay is adapted to open the contact 21 when the engine speed drops to a value at which the current tends to flow from the battery to the generator (arrow 25), this value being close to the cut-out speed which is close to the idling speed. Of course, a member responsive to the cut-out and regulator unit, or a centrifugal switch, or any other suitable device may be substituted for this relay.

A main switch 26 on the instrument panel of the vehicle is also provided in the circuit of the electromagnet 14.

On the other hand and as shown in FIG. 3 the shutter 9 of the device may also act as a substitute for the regulator air shutter in order to simplify the arrangement. In this case the lever 11 carrying the electromagnet 14 is connected directly to the rod 4 of the accelerator control, and formed with an extension 11 co-acting with the idling stop 8 and contact 19, as in the case of the lever 6 of the preceding form of embodiment.

This arrangement operates as follows:

When the engine is running under normal conditions at a speed depending notably on the depression of the accelerator pedal, it will be seen (FIG. 2) that the shutters 9 and 2 are open to the same degree due to their operative coupling and to the fact that as the contact 19 is open, the electromagnet 14 is tie-energized although contact 21 is closed, so that the vacuum regulator is operated as usual.

Similarly, in the modified and simplified form of embodiment illustrated in PEG. 3 the shutter 9 will simply follow the movements of lever 11, the lever 17 thus resting normally against the abutment 11' as is the case in FIGURE 2.

When the driver releases completely the accelerator pedal, for example for applying the brakes or changing the transmission ratio, the contact 19 closes and the electromagnet 14 becomes energized so that the shutter 9 closes completely the induction pipe (positions of FIGS. 1 and 3). The engine suction is thus throttled and the relatively high vacuum prevailing in the pipe 1 will increase the vacuum in the reservoir during a time interval lasting for example from the moment when the pedal was released to the moment when, for a predetermined engine speed above the idling speed, the contact 21 opens and the shutter 9 is therefore allowed to resume its inoperative or open position.

During this time interval and in the case considered herein of an engine equipped with a vacuum-controlled regulator, the fuel injection is stopped automatically for the instantaneous vacuum available is sufiicient for restoring the injection pump adjustment member to its neutral position.

However, it will be noted that during the acceleration stroke of the throttle pedal from its inoperative position and notably from the position corresponding to the idling speed of the engine, the contact 19 opens before the contact 21 closes, so that any risk of suddenly stopping or retarding the engine during this phase is definitely avoided.

Although a few forms of embodiment of this invention have been shown and described herein by way of example, it will be readily understood by anybody conversant with the art that many modifications and alterations may he brought thereto without departing from the spirit and scope of the invention as set forth in the appended claims.

I claim:

1. In combination with a diesel engine having an air intake tube leading to an intake manifold and an accelerator control member; a device for obtaining and storing vacuum comprising a shutter operatively mounted in the air intake tube, a vacuum tank, conduit means connecting said tank with the intake tube downstream of said shutter, a non-return valve in said conduit means, means operatively connected to said shutter for actuating the shutter, control means for said actuating means, said control means including means responsive to the position of the accelerator control member and means responsive to the speed of the engine, said control means being provided to cause the shutter to be in a closed position when the accelerator control member is in a rest position and that, simultaneously, the engine turns at a speed at least equal to a given speed slightly higher than the idling speed.

2. The combination of claim 1, wherein said actuating means actuates said shutter in a closing direction and includes an electromagnet, means operatively connecting said electromagnet with the shutter, and an energizing circuit for the electromagnet controlled by said control means, said means responsive to the position of the accelerator control member including an electric contact closed in the rest position of said control member and said means responsive to the speed of the engine comprising a second electric contact mounted in series with said first-mentioned contact in said energizing circuit, said second contact closing when the engine operates at a predetermined speed above the idling speed.

3. The combination of claim 1, wherein said diesel engine includes a vacuum operated regulator, said shutter being of the butterfly type and also being adapted to function as an air shutter for the vacuum operated regulator, a control lever for the accelerator control member, said shutter being mounted with a predetermined angular play relative to the control lever, said actuating means including an electromagnet rigid with said lever and adapted to close the shutter in relation to its position corresponding to the rest position of said accelerator control member.

4. The combination of claim 1, wherein said engine includes a vacuum operated regulator having a regulator shutter, said actuating means including an electromagnet, a lever carrying the electromagnet, means mounting the shutter with a predetermined angular play relative to said lever, means coupling the vacuum operated regulator shutter to the shutter in the intake pipe, both of said shutters having substantially similar positions when the electromagnet is de-energized.

References Cited in the file of this patent UNITED STATES PATENTS 1,741,817 Bragg et a1 Dec. 31, 1929 1,741,820 Bragg Dec. 31, 1929 2,721,629 Saussard Oct. 25, 1955 2,935,167 Stelzer May 3, 1960 FOREIGN PATENTS 354,926 Great Britain Aug. 20, 1931 671,132 Great Britain Apr. 30, 1952 

